Request: Widow control (widont)

This is a great library! Thanks so much for maintaining it.

I'd love to see an option for controlling widows. For instance typogr.js uses the "widont" pattern of replacing the space between the last two words in a block with  .

(Typographically a widow is actually a single line on a wrapped paragraph rather than a single word on a wrapped line, but on the web the usage seems to be mostly about not leaving a single word, since multicolumn layouts are less common.)